Mutation and extinction rates in Adelie penguin (Pygoscelis adeliae) populations from fossil bones and blood samples collected from several sites in the Ross Sea Region

Entry ID:
K030_2001_2005_NZ_1

Summary

Abstract:
Recent studies on the evolution of mitochondrial DNA in Adelie penguins has found high rates of mutation sparking a major controversy and raising the question of whether evolutionary rates are high because of high mutation rates or because of a low rate of haplotype extinction. As a result, this study aimed to measure the rate of mutation using DNA collected from known pedigrees and comparing it ... with the rate of evolution previously determined using DNA collected from ancient bones serially preserved through time. Mutation rates were determined between mitochondrial haplotypes. A series of abandoned Adelie penguin rookeries at Cape Adare was excavated and more than 1000 bones, likely to be the oldest collected in the Ross Sea, were collected. In addition, a separate party worked at sites in Terra Nova Bay including Inexpressible Island, Cape Reynolds, Coulman Island, Cape Adare, Duke of York Island, Edisto Glacier and Crater Cirque where a mixture of blood (Inexpressible Island and Coulman Island) and subfossil bones (all other sites) were collected for this study. Two methods of analysis, MCMC and a least squares regression analysis was used to estimate the rate of evolution in fossil bones, independent of tree topology (where mutation rates are calculated in a different manner). According to the neutral theory, the high rate of evolution of the control region in Adelie penguins is likely to be a consequence of a high mutation rate. Therefore, the rate of mutation for the gene sequence Hypervariable Region I (HVRI) was directly measured using >2,500 Adelie penguin families. Blood samples were collected from adults nesting penguins and their chicks at sites in Terra Nova Bay and Cape Bird.